{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:4HUGXW77DDQVVH6Q4LGGEX7KAZ","short_pith_number":"pith:4HUGXW77","canonical_record":{"source":{"id":"1207.0388","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-07-02T14:02:32Z","cross_cats_sorted":["physics.flu-dyn"],"title_canon_sha256":"8f88d730ec5499cfc985a76a76049918f52e42fd2d40ddab25a4fa382e829a9d","abstract_canon_sha256":"3709011c61f4652de51106dd20598adfb7186308f251fe5294405f678a276c2f"},"schema_version":"1.0"},"canonical_sha256":"e1e86bdbff18e15a9fd0e2cc625fea066bb39846b7874171825fd0d70380c1bf","source":{"kind":"arxiv","id":"1207.0388","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1207.0388","created_at":"2026-05-18T03:34:35Z"},{"alias_kind":"arxiv_version","alias_value":"1207.0388v2","created_at":"2026-05-18T03:34:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1207.0388","created_at":"2026-05-18T03:34:35Z"},{"alias_kind":"pith_short_12","alias_value":"4HUGXW77DDQV","created_at":"2026-05-18T12:26:53Z"},{"alias_kind":"pith_short_16","alias_value":"4HUGXW77DDQVVH6Q","created_at":"2026-05-18T12:26:53Z"},{"alias_kind":"pith_short_8","alias_value":"4HUGXW77","created_at":"2026-05-18T12:26:53Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:4HUGXW77DDQVVH6Q4LGGEX7KAZ","target":"record","payload":{"canonical_record":{"source":{"id":"1207.0388","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-07-02T14:02:32Z","cross_cats_sorted":["physics.flu-dyn"],"title_canon_sha256":"8f88d730ec5499cfc985a76a76049918f52e42fd2d40ddab25a4fa382e829a9d","abstract_canon_sha256":"3709011c61f4652de51106dd20598adfb7186308f251fe5294405f678a276c2f"},"schema_version":"1.0"},"canonical_sha256":"e1e86bdbff18e15a9fd0e2cc625fea066bb39846b7874171825fd0d70380c1bf","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:34:35.463532Z","signature_b64":"CorY2ILlLXGx9+p+Bo9geo/glDb708+IjhjUsJI95k3JIVb5G3AhADWfNZhm0FaLC4par+XA5CT4yWBsgWG4Bg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"e1e86bdbff18e15a9fd0e2cc625fea066bb39846b7874171825fd0d70380c1bf","last_reissued_at":"2026-05-18T03:34:35.463030Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:34:35.463030Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1207.0388","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T03:34:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"n8O0HdPNxylK338pTTYGeR1fkpXckmP+IpkqEYhvOFAIDwNJPqRgHx43YOQUwyYdc6GMNncuXBoXes20lpJvBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T14:36:21.462199Z"},"content_sha256":"04bbbb3532f39acd8480769ebc5c996c91bc82d414d5b57402fdbed66c92b309","schema_version":"1.0","event_id":"sha256:04bbbb3532f39acd8480769ebc5c996c91bc82d414d5b57402fdbed66c92b309"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:4HUGXW77DDQVVH6Q4LGGEX7KAZ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Capacitance matrix technique for avoiding spurious eigenmodes in the solution of hydrodynamic stability problems by Chebyshev collocation method","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.flu-dyn"],"primary_cat":"physics.comp-ph","authors_text":"J\\=anis Priede, Jonathan Hagan","submitted_at":"2012-07-02T14:02:32Z","abstract_excerpt":"We present a simple technique for avoiding physically spurious eigenmodes that often occur in the solution of hydrodynamic stability problems by the Chebyshev collocation method. The method is demonstrated on the solution of the Orr-Sommerfeld equation for plane Poiseuille flow. Following the standard approach, the original fourth order differential equation is factorised into two second-order equations using a vorticity-type auxiliary variable with unknown boundary values which are then eliminated by a capacitance matrix approach. However the elimination is constrained by the conservation of "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.0388","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T03:34:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"u8h45EoTqix8AZPRKRilc68EnML4bAseOo1X132N8eFVqV0OwBrNbHSBmYuMxaLZPDp/c9EXZQ2uVkhKMnAAAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T14:36:21.462583Z"},"content_sha256":"feb06aa77ca263e90c214e1fa833b2064ff7bd34b794f673c8828c5054768610","schema_version":"1.0","event_id":"sha256:feb06aa77ca263e90c214e1fa833b2064ff7bd34b794f673c8828c5054768610"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/4HUGXW77DDQVVH6Q4LGGEX7KAZ/bundle.json","state_url":"https://pith.science/pith/4HUGXW77DDQVVH6Q4LGGEX7KAZ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/4HUGXW77DDQVVH6Q4LGGEX7KAZ/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-28T14:36:21Z","links":{"resolver":"https://pith.science/pith/4HUGXW77DDQVVH6Q4LGGEX7KAZ","bundle":"https://pith.science/pith/4HUGXW77DDQVVH6Q4LGGEX7KAZ/bundle.json","state":"https://pith.science/pith/4HUGXW77DDQVVH6Q4LGGEX7KAZ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/4HUGXW77DDQVVH6Q4LGGEX7KAZ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:4HUGXW77DDQVVH6Q4LGGEX7KAZ","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"3709011c61f4652de51106dd20598adfb7186308f251fe5294405f678a276c2f","cross_cats_sorted":["physics.flu-dyn"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-07-02T14:02:32Z","title_canon_sha256":"8f88d730ec5499cfc985a76a76049918f52e42fd2d40ddab25a4fa382e829a9d"},"schema_version":"1.0","source":{"id":"1207.0388","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1207.0388","created_at":"2026-05-18T03:34:35Z"},{"alias_kind":"arxiv_version","alias_value":"1207.0388v2","created_at":"2026-05-18T03:34:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1207.0388","created_at":"2026-05-18T03:34:35Z"},{"alias_kind":"pith_short_12","alias_value":"4HUGXW77DDQV","created_at":"2026-05-18T12:26:53Z"},{"alias_kind":"pith_short_16","alias_value":"4HUGXW77DDQVVH6Q","created_at":"2026-05-18T12:26:53Z"},{"alias_kind":"pith_short_8","alias_value":"4HUGXW77","created_at":"2026-05-18T12:26:53Z"}],"graph_snapshots":[{"event_id":"sha256:feb06aa77ca263e90c214e1fa833b2064ff7bd34b794f673c8828c5054768610","target":"graph","created_at":"2026-05-18T03:34:35Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"We present a simple technique for avoiding physically spurious eigenmodes that often occur in the solution of hydrodynamic stability problems by the Chebyshev collocation method. The method is demonstrated on the solution of the Orr-Sommerfeld equation for plane Poiseuille flow. Following the standard approach, the original fourth order differential equation is factorised into two second-order equations using a vorticity-type auxiliary variable with unknown boundary values which are then eliminated by a capacitance matrix approach. However the elimination is constrained by the conservation of ","authors_text":"J\\=anis Priede, Jonathan Hagan","cross_cats":["physics.flu-dyn"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-07-02T14:02:32Z","title":"Capacitance matrix technique for avoiding spurious eigenmodes in the solution of hydrodynamic stability problems by Chebyshev collocation method"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.0388","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:04bbbb3532f39acd8480769ebc5c996c91bc82d414d5b57402fdbed66c92b309","target":"record","created_at":"2026-05-18T03:34:35Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"3709011c61f4652de51106dd20598adfb7186308f251fe5294405f678a276c2f","cross_cats_sorted":["physics.flu-dyn"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-07-02T14:02:32Z","title_canon_sha256":"8f88d730ec5499cfc985a76a76049918f52e42fd2d40ddab25a4fa382e829a9d"},"schema_version":"1.0","source":{"id":"1207.0388","kind":"arxiv","version":2}},"canonical_sha256":"e1e86bdbff18e15a9fd0e2cc625fea066bb39846b7874171825fd0d70380c1bf","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e1e86bdbff18e15a9fd0e2cc625fea066bb39846b7874171825fd0d70380c1bf","first_computed_at":"2026-05-18T03:34:35.463030Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:34:35.463030Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"CorY2ILlLXGx9+p+Bo9geo/glDb708+IjhjUsJI95k3JIVb5G3AhADWfNZhm0FaLC4par+XA5CT4yWBsgWG4Bg==","signature_status":"signed_v1","signed_at":"2026-05-18T03:34:35.463532Z","signed_message":"canonical_sha256_bytes"},"source_id":"1207.0388","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:04bbbb3532f39acd8480769ebc5c996c91bc82d414d5b57402fdbed66c92b309","sha256:feb06aa77ca263e90c214e1fa833b2064ff7bd34b794f673c8828c5054768610"],"state_sha256":"557e2718551bcf6cfacd1da8ed59f1262472225da9faa7432424f507c35dd7d0"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"h3bW4JaSLOeQGka28K4fkstO4QWCCmtx39uKmo0WSB/JtNtfdkFgtOgSmyfnJVqLSMZ1OqvEuH6ck4++EVvgDw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T14:36:21.464505Z","bundle_sha256":"6587e415c627b2911478fc4fe296fe8612bbb3935c045c1c4b414648eb301bd5"}}